The present invention relates to an aggregate for feeding fuel from a supply tank to an internal combustion engine of a motor vehicle.
Aggregates of the above-mentioned general type are known in the art. One such aggregate is disclosed for example in the German patent document DE-A 40 20 520. This aggregate has a rotatingly driven feed element in the form of an impeller arranged in a pump chamber. The impeller supplies fuel from a suction opening which opens in the pump chamber to a pressure opening which leads from the pump chamber. A groove-shaped unloading passage is provided in a chamber wall which limits the pump chamber in the region of a sealing surface. It communicates through a corresponding opening the pump chamber with a region of the system in which the low pressure acts. Gas bubbles are discharged in the unloading passage, which due to the gaps available between the impeller and the pump chamber, flow from the pressure opening to the suction opening and therefore can disturb the operation of the feeding aggregate during their aspiration. The unloading passage is arranged near the pressure opening. It has the disadvantage that the gas bubbles which flow back opposite to the rotary direction of the impeller in front of the unloading passage to the suction opening, can reach the suction opening and again can be aspirated there so as to disturb the operation.